1. Field of the Invention
The present invention relates generally to radio-over-fiber based networks. More particularly, the present invention relates to a system for interoperating a full-duplex radio-over-fiber network in a fiber-to-the-home network and to a method associated with the system.
2. Background Information
For the future provision of broadband and other multimedia services over wireless media, current trends in cellular networks are to reduce cell sizes to accommodate more users, and to operate in the microwave or millimeter wave frequency bands to avoid spectral congestion in lower frequency bands. Such scenario demands a large number of base stations to cover a service area which shall involve relatively high costs. The scenario has led to the development of system architecture where functions such as routing or processing, handover and frequency allocation are carried out at a central or control station instead of the base station. This development allows sensitive equipment to be located in safer environment and enables cost of expensive components to be shared among other base stations.
Wireless networks based on radio-over-fiber (RoF) technologies have been proposed as a promising cost-effective solution to meet ever increasing user bandwidth and wireless demands. The RoF involves a transmission of radio signals over fiber with simple optical-to-electrical conversion and radiation via remote antennas that is connected to the central station. In the RoF, the base station has no processing means or functions as the base station is used to convert optical signal to wireless one and vice versa.
The high data rate and broadband demands of wireless and wired-line networks have rapidly increased in recent years. The RoF and fiber-to-the-home (FTTH) systems are promising candidates which one of the concerns is to transmit both radio-frequency and baseband signals on a single wavelength over a single fiber. However, simultaneous modulations and transmissions of the signals which produce a hybrid resulting signal suffer from many drawbacks such as performance fading and failure to interoperate within the FTTH system.
The typical prior art approach includes to incorporate optical couplers for diverting the received millimeter wave (mm-wave) signal into multiple transmission paths, or sometimes referred to as optical reused carrier. US Patent No. 2011/0069964 describes an optical single sideband mm wave generation for optical wireless network where an intensity modulator is employed at each of the base stations so as to produce the optical mm-wave carrier with double of the local oscillator frequency. The prior art fails to anticipate a system which utilizes a RoF network that is interoperated within a FTTH network.
A need therefore exists for providing an improved system and method for interoperating or integrating the RoF network over the FTTH network. Thus, the present invention seeks to provide a system for communication between a radio-over-fiber based network and a fiber-to-the-home network and a method associated with the system.